A good water trap at the machine helps. Also, getting some spare nozzles, gloves and plastic film for the window. Bulbs, too. Nothing worse than being in the middle of blasting something and the light goes out.

I've used 60 grit red garnet for the past 10 years of so. Seems to do the job without warping anything and leaving great grip for paint. https://www.mcmaster.com/8072T67/